Use when the app needs to store or read data — records, a database, entities, CRUD, lists, "save/remember X", or per-user data with row-level security. This app's data layer is Rayfin's: you declare entities as TypeScript classes with decorators in packages/data/src/, register them in the schema, and read/write them through the typed rayfin-client.
Install
npx skills add microsoft/rayfin --skill data-modelingnpx skills add microsoft/rayfin --skill data-modeling -a claude-code -gnpx skills add microsoft/rayfin --skill data-modeling -a codex -ggemini skills install https://github.com/microsoft/rayfin.git --path samples/universal-app/template/.agents/skills/data-modelinggh skill install microsoft/rayfin data-modelinggit clone --depth 1 https://github.com/microsoft/rayfin /tmp/microsoft__rayfin
mkdir -p ~/.claude/skills ~/.agents/skills
cp -R /tmp/microsoft__rayfin/samples/universal-app/template/.agents/skills/data-modeling ~/.claude/skills/data-modeling # Claude Code
cp -R /tmp/microsoft__rayfin/samples/universal-app/template/.agents/skills/data-modeling ~/.agents/skills/data-modeling # Codex, Cursor, Gemini CLI, Copilot, OpenCode